Hello, could someone help me with a swedish webpage?

Site URL: http://www.interiorart.se

Hi there, I wanted to add a store to my webpage but I realised that I can't customize the text for shopping cart/ checkout/ customer notifications in swedish. The support told that one can add a code but this is so out of my competence. Is there anyone who could assist me with my problem? 

Hi,

Possibile to change shopping cart text

Impossible to change checkout,  customer notification text.